Vacuum cleaning apparatus to remove industrial waste from machinery

ABSTRACT

Textile vacuum cleaning apparatus for automatically providing in timed sequence repetitive, intermittent implosions of waste into a piping system having therein a waste receiving tank for collecting the imploded waste, in which the receiver tank is automatically and intermittently unloaded each time an implosion occurs without interrupting the implosions and in which waste imploded into such piping system by such implosions is collected in said receiver tank between implosions, whereby the size of the receiver tank can be substantially reduced and whereby the waste collected in the tank between implosions is not subjected to the surging action of subsequent implosions.

llnlitenl tntes tet [72] Inventor Oliver 1111. Ramo North Abington, Mass. [21] App]. No. 870,487 [22] Filed Oct. 113, 1969 [45] Patented Dec. 21,1971 [73] Assignee Abington Textile Machinery Works, Inc. North Abington, Mass.

[54] VAClU'UM CLEANIING APPARATUS TO REMOVE llNUl/STRHAL WASTE FROM MACllllllNlERk' 17 Claims, 10 Drawing Figs.

52 vs. (II 15 352, 15/301,15/404 [51] int. (31 A471 S/ [50] lFieldl of Search..... 15/301, 314, 340, 352; 55/302, 417, 432

[56] References Cited UNITED STATES PATENTS 239,190 3/1881 Powell l5/314X 2,409,008 /1949 Acheson /352 X 2,616,557 11/1952 Gill eta]. 55/417 ro POWER SUPPLY 2,784,440 3/1957 Newport.. 15/340 2,977,181 3/1961 Reiterer 15/301 X 3,011,205 12/1961 Holtzclaw 15/352 X 3,423,906 1/1969 Fried /432 X 3,471,890 10/1969 Ramo 15/301 Primary Examiner-Edward L. Roberts Assistant Examiner-C. 14. Moore Attorney-Bronstein & Brown ABSTRACT: Textile vacuum cleaning apparatus for automatically providing in timed sequence repetitive, intermittent implosions of waste into a piping system having therein a waste receiving tank for collecting the imploded waste, in which the receiver tank is automatically and intermittently un loaded each time an implosion occurs without interrupting the implosions and in which waste imploded into such piping system by such implosions is collected in said receiver tank between implosions, whereby the size of the receiver tank can be substantially reduced and whereby the waste collected in the tank between implosions is not subjected to the surging action of subsequent implosions.

PATENTED mm mm 3,628,213

SHEET 1 BF 6 22 25 4s 5 28 3O 50 T0 50 I POWER SUPPLY .I .3! I I .H M

INVENTOR AT TORNEYS PATENTEU 05021 rem 3,628,213

SHEET 2 OF 6 23 MIA/I40 HQ Q INVENTOR OLIVER H. RAMO BY M awn ATTORNEYS PATENTED m2: I97! 3,628,213

SHEET 3 [IF 6 INVENTOR OLIVER H. RAMO ATTORNEYS FMENTED DECZI I971 SHEET [If 6 INVENTOR OLIVER H. RAMO BY M W @MZQM FIG. 5

ATTORNEYS ATENIED DEIIZI Ian 3628213 SHEET 5 [IF 6 \NVENTOR OLIVER I'L R AMO BY 1 W ATTORNEYS SHEET E OF 6 INVENTOR OLIVER IH. RA

ATTORNEYS VACUUM (IlLlEAhlllhlG APPARATUS T lltlEMQVE IINDUSTRHAL WASTE lf'lltUl'l/f lllillllflllfllhllhlmf SUMMARY OF THE lNVENTlON My copending patent application Ser. No. 671,646 filed Sept. 29, 1967, and now US. Pat. No. 3,471,890, describes an electropneumatic vacuum cleaning apparatus for periodically removing industrial wastes, such as waste fibers and trash, from a plurality of processing units, such as textile machinery, as such wastes accumulate at a plurality of accumulation points. Such apparatus comprises a continuously operating air pump which periodically sucks the accumulated wastes from the accumulation points through a conduit system, having an individual inlet at each accumulation point, and into an enlarged waste receiver tank, where the waste is removed from the air stream, with the air stream being sucked from the tank by the pump. The conduit system is provided with a waste valve for each inlet or group of inlets, which may be referred to as a station, so that there is a valve for each station. Actuation of the valves is controlled to individually open and close them one at a time, automatically, successively and repetitively according to a predetermined time program in which each valve remains open for a predetermined first time interval and is closed for a predetermined second dwell time interval before the next succeeding valve'is opened and during which all the valves are substantially closed, tothereby build up the vacuum in the conduit system so that when the next succeeding valve is opened, a sudden violent implosion of waste and air occurs into the inlet of, and through, such next succeeding valve.

In such a system, it is necessary to periodically unload from the waste receiver the waste collected therein so that the conduit system does not become plugged and hence inoperative. During the time that such tank is unloaded, the implosions must be interrupted for what is called a skip or down time. in order to reduce the number of interruptions to a minimum, cumbersome receiver tanks of relatively large size, e.g., 70 inches high, 48 inches in diameter and 75 cubic feet in volume, are employed and the down time may be in the order of 70 to 90 seconds. This is generally true of all industrial vacuum cleaning system whether or not implosions are used.

During each down time, waste continues to accumulate at the accumulation points and care must be taken to control the duration of the down time with respect to the implosion cycle time, i.e., the time from the opening of a valve to the next opening of the same valve with all other valves being successively opened and closed in the meantime, to ensure that when the implosion cycle is recommenced the accumulations have not been so great that the inlets become choked, thereby rendering the system inoperative. This is a danger in waste vacuum cleaning systems generally with or without the use of implosions.

However, even if the skip time and cycle time are regulated so that choking is avoided, efficiency of waste remove is sharply reduced because of the required interruptions. Actually the necessity of unloading reduces efficiency by onehalf or more.

One approach to correct this situation is to add an alternate waste receiver tank and arrange the two receivers so that one is switched into the vacuum system when the other is switched out of the vacuum system. However, this has the disadvantage of being very expensive and creates other problems.

Another disadvantage of the aforesaid implosion technique is that each implosion at the inlets is felt as a surge in the receiving tank, which causes the waste collected in the receiver tank from preceding implosions to be churned and milled around like snowflakes in a snowstorm. As the receiver gradually fills up with incoming waste, the churning and milling action decreases and the incoming waste delivered by the air surges is then stuffed into the receiver. The fibrous waste, e.g., cotton comber noils, subjected to this churning, milling and stuffing bring a lower price because such action decreases their quality and their appearance. When it is remembered that with large conventional receiving tanks of conventional size and the number of implosions required to fill the tank may be as many as 300 or more, it is apparent that the aforesaid quality reducing action is substantial. Even without implosion techniques, i.e., with each inlet valve being opened as the preceding one is closed or with all inlets open to the vacuum at the same time the air moving through the receiver tends to disturb the cotton noils already collected therein to reduce their quality.

it is an object of the present invention to provide a vacuum cleaning system apparatus which overcomes and avoids the aforesaid disadvantages.

This is achieved in accordance with the present invention by unloading the receiver each time that an inlet valve is opened without interrupting the intermittent and repetitive vacuum applications at the inlets. When the implosion technique is used, the receiver is unloaded during each implosion without interrupting the implosion cycle. During the subsequent dwell time more waste is collected in the receiver tank from previous implosions which is unloaded during the next implosion. Accordingly, the size of the receiver can be substantially reduced, the waste collected from the preceding implosions is not subjected to the churning action of subsequent implosions or of the flow of air through the receiver where implosions are not used, and waste removing efficiency is increased because the necessity of interrupting the vacuum applications or implosions at the inlets is eliminated.

Unloading of the receiver in this way without interrupting or disturbing the intermittent applications of vacuum to the inlets is achieved in accordance with the present invention by providing a one-way check valve between the receiver tank and the inlet valves which prevents the backflow of air from the receiver tank to a substantial volume of the conduit system adjacent the inlet valves while permitting free flow of air and waste in a reverse direction by the suction action of the pump.

A vacuum shutoff valve for cutting off the receiver tank from the vacuum pump is provided between the receiver tank outlet and the pump inlet preferably as close as possible to the receiver tank outlet, together with provision for releasing the vacuum in the receiver tank, e.g., by connecting it with the atmosphere, when the shutoff valve is closed. The vacuum releasing connection between the receiver tank and atmosphere is closed when the shutoff valve is open.

Preferably, the shutoff valve and vacuum release are synchronized with the inlet valves so that the shutoff valve is automatically closed to cut off the receiver tank from the pump and the vacuum in the cutoff receiver tank is automatically released each time an inlet valve is opened to provide an implosion and so that the shutoff valve is automatically opened and the vacuum releasing connection between atmosphere and the receiver tank is automatically closed when the inlet valve is closed and during the succeeding dwell time to thereby permit the build up of vacuum in the receiver tank during such dwell time.

The receiver tank is also provided with a waste removal bottom door, which when opened, permits the waste collected in the receiver tank to fall out and the operation of which is synchronized with the vacuum cutoff valve, with the vacuum release for the receiver tank and with the inlet valves so that each time an inlet valve opens to initiate an implosion and the cutoff valve is shut and the vacuum is released from the receiver tank, as aforesaid, the door is opened and so that each time such inlet valve is closed to initiate a dwell time and the shutoff valve is shutoff and the vacuum releasing connection between receiver tank and atmosphere is closed, as aforesaid, the door is shut and sealed. Accordingly, each time an inlet valve opens during an implosion, the vacuum shutoff valve is at the same time automatically closed to cut off the receiver tank from the vacuum pump, the residual vacuum in the cutoff receiver tank (built up during the preceding dwell time) is automatically released and the waste removal door is automatically opened to unload the receiver tank and when such inlet valve is subsequently shut to initiate the succeeding dwell time the shutoff valve is at the same time automatically opened, the connection between receiver tank and atmosphere is automatically shut off and the waste removal door is automatically closed and sealed to thereby seal the system (all the inlet valves are closed) and permit the vacuum to be built up during such succeeding dwell time, during which time waste pulled through the inlets during a preceding implosion or implosions is drawn into the receiver tank for removal during the next implosion.

When the receiver tank is opened to the atmosphere during unloading to release the vacuum in the receiver tank, the oneway check valve (closed by the inrush of the higher pressure air into the receiver tank) prevents backflow of such inrushing air from the receiver to the conduit system adjacent the inlet valves, i.e., between the receiver tank and the inlet valves, and hence prevents the implosion creating vacuum in such conduit system from being destroyed by virtue of releasing the vacuum in the receiver tank. In effect the check valve isolates the vacuum in such conduit system from the receiver tank.

The volume of the conduit system between the one-way valve and the inlet valves should be sufficient so that the vacuum created therein during the preceding dwell time is sufficient on closing of the one-way valve to provide the desired implosive force at the inlet in spite of the fact that such volume is shut off from the vacuum pump and receiver tank.

The volume required to do this depends on the degree of vacuum produced by the pump, i.e., the capacity of the pump.

inlet, which is usually the minimum required for efficient operation, it is usually necessary to implode 2.88 cubic feet of air into the inlet on opening the inlet valve, i.e., 5.75 ft. are required per lb. of imploded waste. Accordingly if an absolute vacuum, Le. 30 inches of mercury, were possible, the volume of the conduit system between the inlet valves and the oneway check valve to draw one-half pound of cotton into each inlet per implosion should be at least 2.88 ft". With a 6-inch vacuum, such volume should be at least 30/6 or times 2.88 ft. or 14.4 ft". In terms of a 6-inch O.D. pipe of /B-II'ICI'I pipe wall thickness conventionally used for these vacuum-type systems (such pipe has a volume of 1 cubic foot per 5.55 linear foot of pipe), this represents 80 linear feet. Conventional textile vacuum cleaning systems of this type have more than 80 linear feet between the inlet valves and the waste receiving tank. With a -inch vacuum such volume should be at least 30/10 or 3 times 2.88 ft. or 8.64 ft, this being equivalent to 48 linear feet of the aforesaid 6-inch O.D. pipe.

However, the minimum 2.88 ft. volume of the conduit system between the inlet valves and one-way check valve is based on optimum results and may be varied considerably, depending on the weight of waste to be imploded into the system in each implosion and also on the diameter of the inlets. It will be clearly apparent to one skilled in the art from this disclosure what such volume should be for any given vacuum to pull any desired amount of cotton waste into any particular inlet.

To summarize, the receiver tank may be connected with the atmosphere and unloaded during each implosion and without disrupting the implosions or the dwell time required to build up the necessary vacuum by utilizing the aforesaid one-way valve together with the aforesaid minimum conduit volume between the one-way valve and the inlet valve.

Although it is preferred to unload the receiver tank during each implosion, it can be unloaded intermittently during only certain implosions in the cycle, e.g., every second or third or fourth implosion, with advantageous results.

Also the same techniques can be used to advantage with systems in which one valve is opened while the other is being closed so that the vacuum intennittently applied is not in the form of an implosion and in systems in which all the inlets are open at one time. However, in the latter case much of the advantage of the invention is lost.

An important advantage of the invention is that the vacuum shutoff valve, vacuum releasing means and the waste removing door can be controlled to unload the receiver tank in synchronization with the inlet valves from the same multicam program timer used to control the inlet valves.

Important advantages of the decreased size and weight of the receiver tank are that they permit the vacuum therein to be released in a fraction of a second and to be built up quickly and they permit the door to be opened in a fraction of a second and closed in a fraction of a second so that the operation of the door and vacuum release to unload the waste receiving tank during each implosion can be automatically synchronized with the intermittent, repetitive opening and closing of the inlet valves without increasing the implosion and dwell times, without decreasing vacuum build up or implosive force and without interrupting the implosion cycle.

Other objects and advantages of the invention will be apparent from the following description with reference to the accompanying drawings, which describe and show a preferred embodiment of the invention.

DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a diagrammatic view of a waste removal and conveying system embodying the present invention as applied to the waste noils accumulations at a plurality of textile cotton comber machines. I

FIG. 2 is a view in elevation and in section of the waste receiver tank of FIG. 1 during a dwell time showing the vacuum cutofiyalve in open position, the one-way valve in open position and the waste removing door closed in full lines and open in broken lines.

FIG. 3 is a section taken along the line 3-3 of FIG. 2 but with the one-way valve shut during an implosion.

FIG. 4 is an enlarged view of the vacuum cutoff valve of FIG. 1 and its electropneumatic control.

FIG. 5 is a view taken along the line 5-5 in FIG. 4.

FIG. 6 is a diagrammatic section taken along the line 6-6 of FIG. 5 with the vacuum cutoff valve open and with communication between the waste receiver tank and atmosphere cut off during a dwell period.

FIG. 7 is like FIG. 6 but with the vacuum cutoff valve closed and the receiver tank in communication with the atmosphere during an implosion.

FIG. 8 is an exploded view in perspective of the vacuum cutoff valve of FIGS. 6 and 7.

FIG. 9 is a view in elevation of one of the single pole double throw switches in the multicam program timer of FIG. 1.

FIG. 10 is a circuit diagram of the timer of FIG. 1 showing how the circuits of the electropneumatic controls for the inlet valves, the vacuum cutoff valve and the waste removal door of the waste receiving tank are connected during an implosion when one of the switches is in position to open one of the inlet valves.

DETAILED DESCRIPTION In the figures, 2 represents a vacuum system embodying the invention and applied to a Saco-Lowell cotton comber Model having a plurality of comber heads 4, 4a, 4b, 4c, 4d, 42 and 4f, to remove from the situs of the heads the accumulations 6, 6a, 6b, 6c, 6d, 62 and 6f, of cotton noils as they accumulate at accumulation points at the heads, such points being also represented as 6, 6a, 6b, 6c, 6d, 6e and 6f in FIG. 1. Located closely adjacent to, or at (under in the case of FIG. 1), each accumulation point is the waste inlet opening 8, 8a, 8b, 8c, 8d, 82 and 8f, respectively, a conduit (piping) system 7 made up of a branch 10, 10a, 10b, 10c, 10d, 10a and 10f, respectively, for each waste inlet, a manifold portion 14 into which all the branches 10-l0f, feed, and a portion 16 which extends from the manifold portion 14 to the air inlet 17 of a waste receiver and collection tank 18, which is substantially smaller and lighter in weight than the size and weight of conventional waste receiver tanks, the receiver tank shown in the drawings being l9 inches in diameter, 21 inches in height and 3% cubic feet in volume (these dimensions are by way of example only and are not by way of limitation).

Tank lid is provided with a one-way check valve 2'7 in the form of a rubber flap valve at its inlet 2i and has a screen 269 of conventional design extending across the top thereof between the air and waste inlet 17 and the air outlet hll of the tank to remove waste noils from the airstream passing through the tank from inlet 117 to outlet 21. The waste noils collect in tank lid. The air outlet 21 is connected to the suction inlet of a conventional, multistate, centrifugal air (vacuum) pump 26 by means of a second conduit system 2.2, in which is located (a) close (preferably as close as possible) to the outlet 21 of the tank llh a vacuum cutoff valve assembly 23 (shutter valve) pneumatically actuatable to open and close communication between the receiver tank lid and the vacuum pump 26 and (b) close to the pump inlet 25, a conventional blast gate 24 to control total airflow through the pump. The exhaust 2% from pump 26 is returned to the atmosphere and the pump is driven by a motor Ell).

Located in each of the branches ll-ltif of conduit system 7, as close as possible to the waste inlet f of such branch, is a shutter valve 12, Ma, 12b, 120, Md, 1122 and llZf, respectively, each of which is of like construction and is pneumatically actuated by a conventional air cylinder (and piston) 32, 32a, 32b, 32c, 32d, Me and 32f, respectively, e.g., the air cylinder and piston assembly sold by Reidy Corporation under the trade name ll/llLlLElR AIR CYLINDER. Reciprocal movement of the piston inside the cylinder reciprocally pivots the shutter valve liZt-llZf controlled thereby to open and close positions, the shutter valve being pivotally moved in one direction by movement of the piston in one direction to open the valve and in an opposite direction by movement of the piston in an opposite direction to close the valve. The shutter valve cornprises a flat shutter plate with a hole in it having a diameter equal to the internal diameter of the branch pipe lltl-lltlf in which it is located. The valve is opened by pivoting the shutter plate in the aforesaid one direction to align the hole in the shutter plate with the internal pipe diameter and is closed by pivoting the shutter plate in the aforesaid opposite direction to block the pipe by a solid part of the valve plate. The valve is essentially of the same construction as the vacuum shutoff valve 23 which will be described in greater detail hereinafter.

The operation of each air cylinder is controlled by a con ventional solenoid operated pneumatic pilot valve, 3%, Elba, ddb, 3hr, Mid, Chic and 3%), respectively, one example. of such a solenoid controlled pilot valve being the one sold by Modenair Corporation under the name MODENATR. Each solenoid controlled pilot valve 3ti-3df has a solenoid controlled spool (not shown), which controls flow of control air under pressure through ports M, 36, Ml, 42 and id of the pilot valve and into and out of the air cylinder controlled by such pilot valve. Energzing the solenoid 45 moves the spool in one direction and directs air from compressed air supply port all through port 3b to one side of the piston in the cylinder to move the piston in a direction to open its shutter valve, exhaust air from the other side of the piston being exhausted through ports lid and dd. Movement of the spool in an opposite direction by deenergizing its solenoid d directs control air from port d2 through port 34 to the aforesaid opposite side of the piston .to move the shutter valve to close position, exhaust air from the aforesaid one side of the cylinder being exhausted through ports 36 and M.

The solenoids d5 of the solenoid controlled pilot valves dhfiflf are controlled, i.e., energized and deenergized in a controlled manner, by a conventional, electric, multicam switch programmed repeat cycle timer dd, e.g., a timer sold by Eagle Signal Corporation under the name MULTiPULSE RE- FEAT CYCLE 'I'IMER, the multicam operated single pole, double throw switches d9 (FIGS. 9 and 110) of which are operably connected to the individual solenoids d5 of the pilot valves Bib-3th by electric leads db, dda, dbb, ide, and, dds and dhf, respectively, and which is supplied by electric power at 50 through switch fill.

The timer dd, which is adapted to be programmed as desired by programming the closing and opening of the multicam switches 49 thereof through the synchronous motor 53, is programmed to control (through leads lthinn the individual solenoids of pilot valves Elli-3d and hence shutter valves till-112]", one at a time, successively (first valve til, next valve Illa, next valve 112b, next valve 1120, next valve 112d, next valve 112s and next valve llZf) and repetitively (after valve 12f is opened and closed, valve 12 is again opened and closed and the cycle repeated) and intermittently in accordance with a predetermined time program, in which each shutter valve is open during a first predetermined time interval (e.g., I second) and is closed for a second predetermined dwell time interval (e.g., 3 seconds) before the next succeeding shutter valve is opened and during which all the shutter valves are closed, to thereby build up the vacuum in the conduit system '7, tank lib and conduit 22 (cg. up to 6 or 7 inches of mercury below atmospheric pressure) all downstream of the closed shutter valves ll2ll2f, so that when such next succeeding shutter valve is opened, a sudden, instantaneous, violent implosion (inrush) of waste noils and air into and through such next succeeding valve and its inlet 8-df occurs. The vacuum is thus built up during the dwell time interval because the pump 26 continues to operate while all the valves are thus closed to thereby evacuate the conduit system 7, tank lid and conduit 22, all downstream of the closed shutter valves The first instantaneous time interval, during which each shutter valve is open and the sudden implosion at the inlet h-hf of such shutter valve occurs to suck the accumulated waste 6-bf at such inlet through the inlet and valve into the conduit system, is too short for the pump to convey the imploded waste material entirely through the conduit system 7 into the receiver tank lid. However, the subsequent intermittent flow of air through such conduit system caused by the subsequent implosions, which occur when the subsequent valves are opened or when the same valve is subsequently opened, convey the waste further along the conduit 7 and the build up of vacuum during the subsequent dwell time intervals conveys the waste from the conduit 7 into the receiver tank ih, where it is removed from the airstream by the screen 20 and collects in the tank id as will be more fully described hereinafter. The remaining airstream, with the waste removed therefrom is pulled through conduit 22 and pump 26 out the pump exhaust 2h.

The implosion at each inlet h-hf occurs instantaneously during the aforesaid first time interval after the valve 112-121" is opened. The waste of b-bf is sucked through the valve llZ-ll2f during the initial moment of each implosion when the vacuum in the conduit system 7 is at its maximum, thereby causing the rate of airflow through the valve to be at its maximum. The first time interval is selected so that the valve is closed immediately after such waste is sucked therethrough because if the valve is left open for a longer time, no useful work is being accomplished so that the power required to move air through the valve for such longer time is wasted, as well as pump capacity.

The strongest implosion occurs by selecting the dwell time interval so that the pump builds up in the conduit system '7 and tank lid the maximum vacuum it is capable of building up before the next succeeding valve is opened. The maximum vacuum is achieved when the increase in vacuum, after closing the preceding valve, commences to stabilize, and the dwell time is preferably adjusted so that the next succeeding valve opens when or shortly before this condition is achieved. The actual dwell time as well as the first valve-open time interval depends on the pump capacity, the size of the conduit systems '7 and 22 and the tank ltd, the size and number of the valve openings, the amount of waste accumulations at each inlet til-hf, etc.

Preferably, each of the valves 12-12f is placed as close as possible to its inlet 8-8f so that the vacuum built up during the dwell time will not be dissipated in moving a substantial amount of air in the branch Ill-10f between the valve and inlet to thereby decrease the punch of the implosion of such inlet when the valve is opened. Another reason for placing each valve as close as possible to its inlet is to prevent the development of a compression wave in the high-velocity air between valve and inlet when the valve is suddenly closed with consequent bounce back of air and possibly waste out of the inlet.

As aforesaid, each of the electric leads 46-46f, and hence each of the solenoids 45, is controlled by a cam operated switch 49 in the timer 48, the switches being set to open and close to energize and deenergize the solenoids of pilot valves 38-38f according to the aforesaid program.

Although in FIG. 1, the implosion technique is applied to a plurality of waste accumulation points, it can also be applied with advantage to a single waste accumulation point. In some cases, the waste accumulations from a number of comber heads are channeled to a single point, e.g., in the case of the Saco-Lowell Model 140 Comber. In such cases, the conduit system may have a single inlet valve which services a number of inlets at a number of comber heads and which is alternately and repeatedly opened to provide an implosion and closed for a dwell period, according to a predetermined time program. Furthermore, the same technique can be used for a number of Saco-Lowell Model 140 Combers by providing an inlet valve for each comber. It has been discovered that the relatively large volume of waste fed from a number of comber heads on each comber is easily sucked through the valve into the conduit system by the initial implosive rush of air through the valve when it is opened. Whereas in FIG. 1, each inlet comprises a station served by a valve, in the aforesaid arrangement of the Saco-Lowell Model 140 Combers, each station comprises a plurality of inlets serviced by a single valve.

Although in the above description, only one valve is opened and closed at a time, it is possible to have two or more smaller sized valves, the total cross-sectional area of which is equivalent to the cross-sectional area of one larger valve, to open and close together followed by opening and closing of another or plurality of valves together, with a dwell time between the closing of one set of the opening of the other to build up the vacuum as described in order to achieve the aforesaid implosions.

The waste receiver tank 18 comprises a cylindrical metal shell having the inlet 17 at the upper portion thereof, a flanged, upwardly dished dome top 72 and a bottom formed by a swinging door 74 adapted to swing about the pivot 76 between a closed sealed position, as shown in full lines in FIG. 2 in which position it is urged against the triangularly crossshaped rubber gasket ring 760 (secured to the bottom of shell 70 by the out-turned lip 70a at the lower end of shell 70 and by bracket ring 78 secured by bolts and nuts 78b to an angle iron ring 78a secured around the lower portion of shell 70) to sealably close the receiver tank, and a fully open position, as shown in broken lines in FIG. 2, in which the bottom of the tank is fully open so that the waste accumulated therein drops out of the tank.

Pivot 76 pivotally secures the door 74 to the tank 18 through a pair of parallel pivot brackets rigidly secured to the door and pivotally secured through pivot 76 to a bracket 77 rigidly secured to angle iron ring 78a welded around the lower part of tank shell 70 but spaced therefrom by a pair of steel spacer rings 79. Gusset 79a is secured to the shell 70 and bracket 77 to strengthen the bracket.

. Door 74 is made up of an octagonal-shaped flat plate 82 and a channular steel backing arm 84, the base 85 of which is parallel to the plate 82 and which is secured to plate 82 for a floating movement toward and away therefrom through the bolts 86 and bushings 88. One of the bolts 86 is located at the center of the plate 82. Located around such centrally located bolt 86 between plates 82 and 85 are a resilient rubber disc 75 and a metal disc 92. Upon clockwise swinging of the door 74 to closed position, as shown in full lines in FIG. 2, the plate 82 first engages the rubber triangular-shaped gasket ring 760 (held between lip 70a and bracket ring 78), whereupon further swinging movement of channular member 84 compresses the gasket 76a to form a seal and also causes plate 84 to slide on bushings 88 toward plate 82 to compress the rubber disc 90 and cause door 74 to bear evenly on gasket ring 76a.

A pneumatic piston and cylinder assembly 94 having the same construction as piston and cylinder assemblies 32-32f is pivotally attached at 96 at its piston rod end clevis 96a to the pivot brackets 80 and is pivotally attached at 98 at its cylinder end between parallel brackets 100 which are in turn rigidly secured to an angle iron ring 102 clamped around the upper end of shell 70 and forming a flange on which the flange 72a of top 72 is secured. The pneumatic piston and cylinder assembly 94 is controlled by a solenoid controlled pilot valve 104 having the same construction as the solenoid controlled pilot valves 3838f with ports 106, 108, 110, 112 and 114, corresponding to ports 40, 42, 44, 34 and 36 of pilot valves 38-38f, and a solenoid 116 like solenoid 45 of valves 38-38f for controlling the spool of pilot valve 104. Solenoid 116 is controlled by the timer 48 through circuit 118 (see FIGS. 1, 2 and 10). Port 108 is connected to a source 120 of compressed air to operate the piston and cylinder. The air line 122 between port 114 and the cylinder 94 has an adjustable oneway airflow control valve 124 at the entry of the air line 122 to the cylinder to control, e.g., to restrict, the rate of airflow out of the cylinder, but not into the cylinder.

When the solenoid 116 is deenergized, the spool of pilot valve 104 is moved to retract piston rod 940 of the piston and cylinder assembly 94 to rotate the door 74 counterclockwise about pivot 76 to thereby open the door, e.g., move it from its closed position shown in full lines in FIGS. 1 and 2 to its fully open position shown in FIGS. 1 and 2 in broken lines. This is achieved by the spool connecting the source 120 of compressed air (port 108) with the port 112 and one of the exhaust ports 106 and with the port 114, to cause compressed air to flow from the compressed air source through the air line 123 into the cylinder and to cause exhaust air to flow through line 122 and thence through one of the exhaust ports 106 and 110. The one-way flow control valve 124 can be adjusted to control the rate of movement of the piston and hence the rate of opening movement of the door to slow it down as will be described in greater detail hereinafter. Because of the compressed condition of rubber discs 90 and gasket ring 76, the door remains sealed shut during the initial opening movement of the channular member 84 and piston rod 94a, i.e., there is a slight delay in the door opening.

When the solenoid 116 is energized, the pilot valve 104 is activated to extend piston rod 940 to rotate the door 74 clockwise from open position shown in broken lines in FIG. 2 to the sealed closed position shown in full lines in FIG. 2, the terminal part of the movement of the channular member 84 being relative to plate 82 to thereby compress the rubber disc 96. This closing movement is produced by the spool of pilot valve 104 being moved by energization of the solenoid valve to connect the compressed air source, 120 with port 114 and air line 122 and to connect the air line 123 and port 112 with the other of the ports 108 and 110 to exhaust the air from the piston rod side of the cylinder 94. The flow control valve 124 does not slow down the rate of movement of the piston and door in this direction.

The one-way check and flap valve 27 comprises a circular curvilinear rubber disc 126 having a curvilinear tab 128 extending from an edge thereof upwardly along the inner surface of the tank shell 70 to which it is secured by three circumferentially spaced bolts and nuts 130 and a curvilinear metal backing strip 32. The rubber valve disc is sandwiched between a pair of curvilinear backing plates 134 and 136 to which it is secured at its center by a threaded bolt and out 138. The curvilinear contours of the rubber disc and its backing plates correspond to the contour of the inner surface of the shell 70 at its inlet 17 so that when the assembly is in closed position, as shown in MG. 31, it fits snugly against such surface over the inlet 1'7. The curvilinear contours of the tab 132 and its backing strap 1132 also correspond to that of the inner surface of shell 7li with which it is held in contact so that the tab fits snugly against such surface. The circular rubber disc 1126 and its circular backing plate 11341 are of the same diameter, which is greater than the diameter of the inlet 17 whereas the diameter of the backing plate 136 is smaller than that of the inlet 17 so that when air commences to flow from the tank 11% into the inlet, as for example when the vacuum in the tank is suddenly released (e.g., through outlet 21) at a time when there is a vacuum in the tank and pipe 116, the rubber disc 11% forced tightly against the inner surface of the tank 1% surrounding the inlet 17 to thereby close and tightly seal the inlet, as shown in FIG. 3, to prevent the flow of air from the tank into the pipe 16, thereby preventing the release of the vacuum in the pipe 16 when the vacuum in the tank is released. Put in another way, the higher pressure of the inrushing air into the tank as compared to the low pressure in pipe 116 forces the valve 27 to close and seal before the vacuum in pipe 116 is destroyed. The differential in pressure in the tank, when the vacuum therein is so released, and in the pipe conduit 16 makes a tight seal.

The integral juncture of the main circular part of the rubber disc 1126 and the tab 112% forms a resilient hinge about which the valve swings between close (FIG. 3) and open (H6. 2) positions.

Although the rubber flap valve 27 prevents flow of air from the tank 18 into the pipe 116, it permits free flow of air and waste carried thereby from pipe lo into the tank. Such flow moves the rubber valve to the position shown in FIG. 2 to open inlet 117.

Vacuum shutoff valve 23 comprises a shutter valve of the same type as inlet valves llZ-llZf made up of an oscillating shutter valve plate 11 (FIGS. M) having a hole i412 therein. The shutter plate Ml) is located between fixed plates MM and 1 16 having axially aligned holes 1148 and 150 therein respectively, which are also axially aligned with the internal passages of pipe sections 22a and 22b of pipe 22 on either side of valve 23. The diameters of holes 1143 and 1150 in the fixed plates 11% and M6 and the hole 11412 in shutter plate 140 are all equal and of the same diameter as the internal diameter of the pipe sections 22a and 22b of pipe 22. The fixed plate 11% is rigidly secured to the pipe section 22b with its hole 150 axially aligned with the internal passage of section 2212 and fixed plate 114141 is rigidly secured to pipe section 22a with its hole axially aligned with the internal passage of section 22a, as by threading, as shown in FIGS. 6 and 7.

Shutter plate 1410 is pivotably mounted between and on the fixed plates 11441 and M6 by a suitable pivot pin 152 (also bushing 15d) extending through a hole 153 in the shutter plate and through holes 1530 and 1531b in the fixed plates 11% and M6, respectively, so that it can be reciprocally oscillated (a) in a counterclockwise direction about pivot 152 into open position, as shown in FIGS. 5 and 6, in which the hole M2 thereof is axially aligned with holes 141% and 15111 of fixed plates M41 and lldo and in which communication is provided between the vacuum pump 26 and the tank 15 to thereby provide a vacuum in the tank and in the conduit system 1115, 114, lit-110a and (b) in a clockwise direction into closed position in which the solid portion 156 thereof is located between the holes Md and 15% to block such holes and close the shutter valve, as shown in FIG. 7, whereby communication between the pump 26 and tank 113 is cut off so that the pump no longer sucks air from the tank. The bushing 15 61 has a axial dimension slightly greater than the thickness of shutter plate 1% for free oscillation.

The shutter plate 1410 has a notch 15% in a corner of the solid portion 15b thereof, which, when the valve is in the closed position shown in FIG. 7, provides communication between the tank 13 and the atmosphere ,to thereby release the vacuum in tank 18 which was formed therein while the shutoff valve was open before closing it. Thus the shutter valve is effective to both shut off the vacuum pump from the tank 15 and release the vacuum in the tank when it is closed.

The piston rod end of pneumatic piston and cylinder assembly 16th for the shutter valve Mill and having the same construction as the piston and cylinder assemblies 32-32f, is pivotally fastened to the shutter plate 11410 through a clevis 11611 and a pivot pin 1162 extending through hole 11641 of shutter plate Mill. The head end of the piston and cylinder 160 is pivotably mounted on and between the fixed plates 114141 and 11% through pivot pin res extending through holes 1168 and M9 respectively, of the fixed plates 11441 and M6.

it is noted that the fixed plate 11 141 and 14 16 are spaced from each other along most of their areas so that the piston and cylinder assembly is mounted therebeitween, as shown, but they extend toward each other in the areas 1414a and M611 surrounding the holes Mlh and 15d, respectively, and in the areas which receive the portion of plate M0 containing hole M2 when the shutter valve is moved to close position, in order for the plate 11 1 11 to fit snugly but slidably therebetween at such areas. This may be seen in FIGS. 1, 5 and d. Accordingly, spacer pivot bosses who and 11711) are provided for the pivot pins 116a and 1152, respectively, as shown in FIG. 41. lBolts 1152, ms and 11711 are also used to rigidly secure the two fixed plates 11 141 and 1146 together.

The operation of the piston arid cylinder assembly 1160 is controlled by a solenoid controlled pilot valve 172 which is of the same construction as pilot valves M-Bhf and the spool of which is controlled by a solenoid 117 1 of the same construction as solenoids d5. Solenoid 1741 is controlled from the timer 48 through the electrical circuit 176, which is interconnected with the circuiting controlling the inlet valves and the door 741 of the waste collecting tank 111% as will be described in greater detail hereinafter.

When the solenoid 11741 is energized, the piston rod 176 of the assembly Ml is retracted to oscillate the shutter valve M1) counterclockwise to open position as shown in FIGS. 4, 5 and 6, in which position the vacuum pump 26 is in communication with the tank 118. This is achieved by movement of the spool of the pilot valve to open the air line 17% to the source of compressed air Thtl and at the same time to open the air line 1182 to the atmosphere to exhaust the air in the cylinder on the left-hand side of the piston as viewed in FIG. 5.

When the solenoid is deenergized, the air line 1182 is connected with air pressure source ran and air line 117% is connected with atmosphere to cause the piston rod 176 to be extended to oscillate the shutter valve 11 w clockwise to closed position as shown in FIG. 7 to thereby shut off the vacuum pump from the tank lltl and open the tank 1113 to atmosphere through the slot 153 to thereby release the vacuum built up in tank lid during the preceding dwell period when the shutter valve was open. it is noted that the slot. is moved into vacuum release position only at the end of the closing movement of the shutter valve after the valve has been closed so that the vacuum pump does not suck any substantial amount of air through the slot. it is also noted that when the valve is closed and the tank 1% is vented to the atmosphere through slot 158, the vacuum pump is shut oi? from the slot.

The fixed plate 1% is provided with a pair of slots M5 to permit the air cylinder 116i) and the elbows 147 (connecting the flexible air lines 1178 and 1182 with the cylinder) to swing up and down during the retraction and extension of the piston rod 17 5, the pilot valve 172 and its solenoid 17% being mounted on the outside surface of plate M6.

A one-way airflow control valve 184 of the same construction as airflow control valve 112 1 is located in line 152 next to the cylinder lltit]. Such flow control valve is adjustable by turning adjustment knob 11% to adjust the restriction in the line to restrict flow of air out of the cylinder during retraction of the piston to the open valve. However, the airflow control valve does not restrict flow of air into the cylinder when the piston is extended to close the valve.

Each of the cam controlled switches 49-49 (there is one switch as for each inlet valve) in the timer d9 (see FIGS. 9 and has a normally closed tenninal NC, a normally open terminal NO, a common terminal CT and a switch arm 186 controlled by a cam follower 188 controlled by an adjustable cam 190 attached to the shaft 192 driven by a synchronous electric motor 53. When the shaft 192 rotates the high portion of the cam against the cam follower 188, the switch arm 188 completes a circuit with the NO terminal in which condition the solenoid of the inlet valve controlled by such switch is deenergized to thereby close such valve whereas when the low side of the cam rotates opposite the cam roller it drops and the switch arm 186 completes a circuit with the NC terminal, as shown with respect to switch 49f in FIG. 10, to energize the solenoid of the inlet valve controlled by such switch to thereby open such inlet valve. As seen in FIG. 10, only one NC circuit is closed at a time so that only one inlet valve solenoid is energized at a time. When one NC circuit is closed, the NO circuits of the rest of the switches are closed to thereby deenergize the solenoids of all the other inlet valves. The synchronous motor and cams are so designed that each switch closes its NC circuit for the implosion time interval followed by closing of the NO circuit of such switch for the dwell time interval during which time the NO circuits of all the inlet valves are closed followed by the NC circuit of the next succeeding switch being closed to open the next inlet valve for an implosion through that valve.

It is noted that all of the NO and CT terminals are connected in series and that the solenoid 116 for controlling the door of the waste collecting tank and the solenoid 174 for controlling the shutoff valve are connected in parallel with such series connected terminals so that when all the NO circuits are closed during a dwell time (all the inlet valve solenoids are deenergized) a circuit is completed through all the switches to the solenoids 116 and 174 to energize them. On the other hand, when any of the switch arms of switches 49-49f move into contact with its NC terminal to open an inlet valve (by energization of its solenoid) to produce an implosion through such valve, the aforesaid series circuit is broken to deenergize the solenoids 116 and 174.

Since deenergization of the solenoid 174 activates the piston and cylinder 160 to cause the vacuum shutoff valve 23 to close and to cause the waste collecting tank to be opened to the atmosphere through slot 158 and since deenergization of solenoid 116 activates the piston and cylinder 94 to open the door 74, it may be seen that during each opening of an inlet valve, i.e. during each implosion, (1) the shutoff valve 23 is activated to shut off communication between the vacuum pump and the waste collecting tank and to open communication between the waste collecting tank and the atmosphere through slot 158 to release the vacuum in the waste receiving tank, (2) the inrush of atmospheric air into the waste collecting tank 18 through slot 158 forces the flap valve 27 to close and seal the inlet 17 to thereby prevent release through such slot of the vacuum in conduit 16, 14 and 10-10f between flap valve 27 and inlet valves 12-12f and (3) the waste removing door 74 is opened to remove the waste accumulated in such tank.

However, when the aforesaid switch arm subsequently moves into contact with the NO terminal by rotation of its cam to deenergize the solenoid of its valve and thereby close such inlet valve and commence a dwell time during which all the valves are closed, i.e., all the switch arms are in contact with their NO terminals so that none of the inlet valve solenoids 45 are energized, this energizes both solenoids 116 and 174 through the in-series NO terminals of all the switches 49. Such energization of the solenoid 116 activates the piston and cylinder assembly 94 to swing the door 74 from its open to its closed seal position and the contemporaneous energization of solenoid 174 activates the piston and cylinder assembly 160 to cause the shutoff valve 140 to be oscillated to open position and thereby I) shut off communication between the waste collecting tank and atmosphere through the slot 158 and (2) reestablish communication between the vacuum pump and the waste collecting tank 18 to thereby evacuate air from the waste receiving tank and open the one-way valve 27 to flow of air from conduit 16 into the tank by the vacuum pump.

The fit between the valve shutter and the fixed plates 144 and 146 is snug enough so that when the valve is opened as aforesaid, there is sufficient leakage of atmospheric air into the system to effect the vacuum produced in conduit 22 and tank 18 by the vacuum pump. in fact such leakage is negligible. Since the gasket 76a of the closed door 74 also seals the receiving tank from the atmosphere, the vacuum system made up of the conduits 14, 16 and 10-10f downstream of the closed inlet valves 12-12f, the waste collection tank 18 and the conduit 22 becomes sealed from the atmosphere at about the same time such system is placed in communication with the vacuum pump to thereby rapidly build up a vacuum in such conduit system during the ensuing dwell period until the next inlet valve is opened to cause a sudden implosion into such next valve by virtue of the built-up vacuum. This build up of vacuum during the dwell time moving air from the conduits 16, 14 and 1010f downstream of the closed inlet valves into the tank 18 and thence to the vacuum pump is effective to suck into the waste collecting tank, waste sucked into the conduit 16 and 14 by the preceding implosion or implosions.

Accordingly, each time an inlet valve 12-121" is automatically opened to provide an implosion, the cutoff valve 23 is at the same time automatically closed, the waste collecting tank is automatically opened to the atmosphere through slot 158 to release the vacuum and the waste receiving tank door 74 is automatically opened to unload the waste collected therein during the previous dwell time, and each time the inlet valve is automatically closed, the vacuum shutoff valve is automatically opened, communication between the waste collecting tank and atmosphere is automatically shut off and the waste removing door of the waste collecting rank is automatically closed and sealed to commence a dwell time during which all the inlet valves 12-12f are closed and a vacuum is built up in the system which is effective to move into the tank the waste sucked into the conduit l6, l4 and l0-10f during the preceding implosions.

Thus the waste collecting tank 18 is automatically unloaded during each implosion while waste is sucked into an inlet valve 12-12f into the conduit 16, 14 and l0-l0f, and during each succeeding dwell time, such imploded waste is moved by the vacuum built up from such conduit into the waste collection tank where it is removed from the airstream for unloading during a succeeding implosion. Actually, the waste imploded into the conduit by an implosion is moved along the conduit 1010f, 14 and 16 by succeeding implosions as well as by succeeding dwell periods but the movement thereof into the tank is during the dwell period since the tank is closed to such conduit during implosions.

Unloading during each implosion in this way is made possible by the one-way flap valve 27 which permits vacuum release in the waste collecting tank for unloading purposes without thereby releasing the vacuum in the conduit system 16, 14 and 10-10f between such one-way valve and valves 12-12f, i.e., without interrupting such vacuum, so that such vacuum existing in such conduit system built up during the preceding dwell time is available to provide the implosion required even though the waste collection tank and vacuum pump have been cut off therefrom and the tank has been exposed to the atmosphere. In this way, the waste collecting tank is unloaded during each implosion without interrupting the implosions. In effect, the one-way valve 27 functions to isolate this conduit system from the tank and vacuum pump during each implosion.

During the time that an implosion occurs the air and waste entering through an inlet into the conduit system upstream of one-way valve 27 builds up in velocity. The momentum resulting from this velocity may be of such magnitude so as at times to swing the check valve 27 open and move waste in such conduit system near the check valve into the opened waste receiving tank and out the open door.

It may be seen that the suction potential available in such conduit system 116, M, ltlt-lliif, i.e., the conduit system upstream of the flap valve 27 and between such flap valve and inlet valves 112-112f, to create the required implosion, i.e., the required inrush of air, upon opening an inlet valve and closing the one-way flap valve 27 depends on (1) the degree of vacuum in such conduit system produced by the pump, i.e., vacuum producing capacity of the pump and (2) the volume of such conduit system. The greater the degree of vacuum for the same volume, the greater amount of air and hence waste, which can be imploded into the inlet when the inlet valve opens and the flap valve 27 closes. The greater the volume of such conduit system for the same degree of vacuum, the greater the amount of air, and hence waste, which can be imploded into the inlet. In the case of a complete vacuum (30 inches of mercury) such conduit system will suck into the inlet a volume of air equal to its oum volume. With a vacuum of 6 inches of mercury it will suck into the inlet a volume of air equal to six-thirtieths of its own volume. Accordingly, if its volume is decreased, it will suck in less air.

For example, with conventional inlet diameters, about 5.76 ft. of inrushing air is required to implode into the inlet 1 pound of waste cotton. in most textile operations, it is sufficient if one-half pound of waste is imploded into the inlet each time an inlet valve is opened. To do this, it is necessary to convey and implode 2.88 cubic feet of air into the inlet each time the inlet valve is opened. Accordingly, if a vacuum of 6 inches of mercury is to be used, the conduit volume between the oneway flap valve 27 and the inlet valves l12-ll2f should be 30/ 6 of 2.88 or 14.4 ft. or more. In terms of a conventional 6-inch. 0.1). pipe of ya-inch wall thickness which has a volume of 1 cubic foot per 5.55 running feet, this amounts to 80 linear feet of pipe. It is usually best to have a substantially greater volume than the minimum required to insure adequate waste removal and to insure movement of such waste well past the inlet valve during each implosion. The pipe volume between the valve in lets and the waste receiving tank in conventional textile vacuum cleaning systems is more than enough.

Given the aforesaid requirements of volume and degree of vacuum, the minimum conduit volume required between flap valve 27 and inlet valves ll2-ll2f for any given degree of vacuum to be used to provide the implosion force desired can be easily calculated by one skilled in the art. If less waste is to be removed during each implosion, the volume for any degree of vacuum can be reduced. If more waste is to be removed for any degree of vacuum, the volume can be increased, consistent of course with the capacity of the pump to build up the degree of vacuum to be used.

Actually, the implosion may commence slightly before the flap valve 27 is sealed shut because the latter occurs upon the slot ifib being moved to a position in which it vents the tank 318 to the atmosphere and this may trail slightly the com mencement of the implosion, i.e., the commencement of the opening of the inlet valve.

The chief purpose of the one-way flow control valve 11% for the piston and cylinder assembly we is to slow down the rate of retraction of the piston 1176 and hence to slow down the rate at which the shutter valve M is opened in order to insure that the waste removing door 74% is fully closed and sealed before the vacuum shutoff valve M0 is opened. Thus, when the solenoids 1174 and 1116 for the shutoff valve and door, respectively, are energized simultaneously, the piston rod Ma for the door is extended at a faster rate than the piston rod 17s for the vacuum shutoff valve is retracted so that the door is closed and sealed before the shutoff valve is open. in this way pump capacity is not expended to draw air into the open door. One of the functions of the compressible rubber disc or pad $0, in addition to absorbing shock, is to permit the piston Win and channel member $41 to continue to move after the plate 32 contacts the gasket '76 and compresses it and until the shutoff valve Mil reaches fully open position. The gasket 76a aids in this respect also. As aforesaid, the slot 158 is so positioned that it is moved out of communication with the tank M before the valve M lt opens the tank to the vacuum pump so that pump capacity is not expended in sucking in air through the slot.

The purpose of the flow control valve 12% in connection with the piston and cylinder assembly for the door 741 is to reduce the shock when the door reaches the end of its fully open swing. Also, the slowing down by such flow control valve of the rate of travel of the door as it opens as well as the lost motion between the door backing member M and the door plate b2 achieved by the rubber plate 9E1) as well as the decompression of gasket 76 delays the door opening until the shutoff valve 114th has been closed and communication between the tank and the atmosphere has been established through slot 15% during each implosion.

The small size of the waste receiving tank provides the following advantages:

1. the door 741 is relatively small and light so that it can be fully opened in a fraction of a second during each of the instantaneous implosion periods. Accordingly, this makes it possible for the door and shutoff valve 23 to be automatically controlled to unload the tank by the same timer control which controls the opening and closing of the inlet valves successfully, intermittently, automatically and repetitively without interfering with the implosion cycle or with the implosions;

2. the small size and weight of the door also permits it to be closed within a fraction of a second so that the required vacuum can be built up rapidly on the closing of each inlet valve without lengthening the duration of the dwell period, which again permits control of the shutoff valve and the door to unload the tank by the inlet valve timer control without interfering with the implosion and dwell time cycle and without sacrifice in the vacuum buildup during the dwell time;

3. the small volume of the waste receiving tank permits the vacuum in the tank to be released instantaneously when the vacuum cutoff valve is closed and the slot 158 opens the tank to atmosphere so that the door 7% can be rapidly opened during each implosion period without interfering with the implosion cycle or with the implosions; again this makes possible the control of the door and shutoff valve 23 to unload the tank by the control for the inlet valves; and

4. vacuum can be built up rapidly in the tank when the eutoff valve 23 is opened without increasing the optimum dwell period, which again permits control of the shutoff valve and door to unload the tank by the same control used for the inlet valves;

5. the power required to operate the door is decreased;

6. the cost of the tank is reduced.

Actually, the size of the tank may be only one twenty-fifth as large as conventional receiving tanks, which are about 75 cubic feet. However, even if the tank is reduced to one-tenth or one-fifth or even one-fourth of conventional size tanks, a substantial advantage is realized. Thus it may range in size from 1 cubic foot to 25 or 30 cubic feet, depending on the particular installation. Preferably it is less than 10 or 11 cubic feet.

in a commercial embodiment in which the volume of the conduit M, M and llll-llllf between the one-way valve 27 and the inlet valves 1242f was 14.4 cubic feet linear feet of a 6-inch 0.11). pipe with zh-inch wall thickness), a waste receiving tank of 3.5 feet, i.e., about 25 percent of the volume of the conduit, performed well. However, it may be substantially less than 25 percent or may be equal to the volume of such conduit. Preferably it is less than 50 percent of the volume of such conduit.

An important advantage of unloading the waste receiving tank during each implosion is that the waste noils collected in the tank during previous implosions is not subjected to the surging action of subsequent implosions to thereby decrease their quality. However, an advantage is gained over the prior art in accordance with the invention even if unloading occurs during every other implosion or during every second or third or fourth implosion or even during only one implosion per cycle or one per two or three cycles since the number of surges to which the collected'waste is subjected is reduced with consequent improvement.

Also, the invention is useful with arrangements in which one inlet valve is opening while the next preceding one is closing without any dwell periods since the unloading operation takes only an instant and during that instant the vacuum in the conduit system upstream of the one-way valve, i.e., between such one-way valve and the inlet valves, is not destroyed or interrupted by releasing the vacuum in the waste collecting tank for the unloading operation. Of course, the circuiting must be changed accordingly. It can even be used, but with less advantage, in a system where all the inlets are open at one time.

It will be understood that the aforesaid explanation and accompanying drawings are only for purposes of explanation of a specific embodiment or embodiments of the invention, and that modifications can be made therein without departing from the spirit of the invention. It is intended that the invention be limited only to the following claims and their equivalents.

I claim:

1. In a vacuum cleaning apparatus for applying a vacuum by a vacuum pump to an accumulation of waste to suck said waste into an inlet of a piping system having therein waste receiving means for collecting said waste and having a first piping section providing communication between said inlet and said waste receiving means and a second piping section providing communication between said waste receiving means and said pump, the improvement comprising in combination a one-way check valve between said inlet and said waste receiving means for preventing backflow of air from said waste receiving means to a substantial portion of said first piping section adjacent said inlet but pennitting free flow of air in an opposite direction, a vacuum cutoff valve in said second piping section for intermittently cutting off said pump from said waste receiving means during an unloading operation, means for automatically opening said waste receiving means to the atmosphere to release vacuum in said waste receiving means when said cutoff valve is closed but not when said cutoff valve is open, said waste receiving means having a waste removing door and means for automatically opening said door when said cutoff valve is closed and said vacuum is released and for automatically closing said door when said cutoff valve is opened.

2. In a vacuum cleaning apparatus for intermittently and repetitively applying a vacuum to a waste accumulation point to suck waste into an inlet of a conduit system having therein waste receiving means for collecting said waste, said apparatus including a vacuum pump for applying said vacuum, the improvement comprising means for intermittently and repetitively unloading said waste receiving means each time a vacuum is applied to said inlet, said unloading means comprising, a one-way check valve between said waste receiving means and said inlet preventing the flow of air from said waste receiving means to a substantial portion of said conduit means adjacent said inlet but permitting free fiow of air in an op posite direction, a vacuum cutoff valve between said waste receiving means and said pump which is closed each time a vacuum is applied to said inlet, means for releasing the vacuum in said waste receiving means when said cutoff valve is closed, said waste receiving means including a waste removing door and means to open said door when said cutoff valve is closed and to close said door when said cutoff valve is opened.

3. Apparatus according to claim 2, including an inlet valve associated with said inlet and located between said inlet and said one-way valve, and control means to (a) intermittently, repetitively and automatically open and close said inlet valve and to (b) intermittently and automatically close said shutoff valve and open said door when said inlet valve is opened and to open said cutoff valve and close said door when said inlet valve is closed.

4. Apparatus according to claim 3, the volume of the conduit means between said one-way valve and said inlet valve at the degree of vacuum delivered by the pump being sufficient to suck the desired amount of accumulated waste at said accumulation point through said inlet valve into said conduit system when said inlet valve is opened and said one-way valve is closed, said one-way valve being closed by the release of vacuum in said waste receiving means.

5. An apparatus according to claim 3, said unloading means being synchronized with said implosions.

6. In a vacuum cleaning apparatus for automatically creating repetitive, intermittent implosions of waste into an inlet of a piping system having therein waste receiving means for collecting said imploded waste, the improvement comprising a one-way check valve located between said waste receiving means and said inlet to prevent the flow of air in a direction from said waste receiving means to said inlet but to permit the flow of air in a reverse direction, means for intermittently building up a vacuum in said piping system during a dwell period between implosions and means located between said waste receiving means and said vacuum buildup means to intermittently shut off communication therebetween and vent said waste receiving means to atmosphere for intermittent unloading of said waste receiving means.

7. In an apparatus for removing and conveying industrial wastes from an accumulation point comprising a vacuum pump, waste receiving and collecting means and a conduit system having an inlet located at said accumulation point and providing communication between said inlet and said waste collecting means and between said waste collecting means and said pump, an inlet wave associated with said inlet and means for actuating said valve to automatically, intermittently and repetitively open and close said valve, the improvement comprising means for intermittently unloading said waste collecting means at a time when said valve is opened, said means for unloading said waste collecting means including a shutoff valve between said waste collecting means and said pump, which is automatically closed each time said inlet valve is opened and is automatically opened each time said inlet valve is closed, means automatically actuatable to open said waste collecting means to the atmosphere when said shutoff valve is closed and to close said waste collecting means to the atmosphere when said shutoff valve is open, a one-way valve for preventing flow of air from the waste collecting means to at least a substantial portion of said conduit means adjacent said inlet valve but permitting fiow of air in a reverse direction, a door for said waste collecting means and means for automatically closing said door when said shutoff valve is opened and opening said door when said shutoff valve is closed.

8. Apparatus for removing and conveying industrial wastes from a plurality of stations, each station comprising at least one waste inlet at which wastes accumulate, vacuum pump means, waste receiving and collecting means, conduit means providing communication from each of said stations to said waste receiving and collecting means and from said last-mentioned means to said pump means, an inlet valve for each of said stations and control means for automatically opening and closing said valves successively and repetitively in accordance with a predetermined time program in which each valve is open during a first predetermined time interval and is closed for a second predetermined dwell time interval before the next succeeding valve is opened and during which all said valves are closed, to thereby build up the vacuum in said conduit means downstream of said values so that when said next succeeding valve is opened, a sudden and violent implosion into and through said next succeeding valve and its station occurs and means for intermittently unloading the waste which collects in said waste collecting means without interrupting the repetitive implosions at said stations, said unloading means including a check valve preventing flow of air from said waste receiving means to a substantial volume of said conduit means adjacent said inlet valves but permitting flow in the opposite direction, said unloading means also comprising a waste removal door associated with said waste receiving means [nd means for releasing the vacuum in said waste receiving means and opening said door when an inlet valve is opened and for deactuating said vacuum release means and closing said door when said inlet valve is closed.

9. Apparatus according to claim also including a vacuum cutoff valve located between said waste receiving means and said pump and synchronized with said inlet valve control means and said vacuum release means and said door to close when said inlet valve is opened and to open when said inlet valve is closed.

W. Apparatus for removing and conveying industrial wastes from a plurality of stations, each station comprising at least one waste inlet at which wastes accumulate, vacuum pump means, waste receiving and collecting means, conduit means providing communication from each of said stations to said waste collecting means and from said waste receiving means to said pump means, an inlet valve for each of said stations to individually open and close communication between said stations and said conduit means and control means to automatically open and close said valves successively and repetitively in accordance with a predetermined time program in which each valve is open during a first predetermined time interval and is closed for a second predetermined dwell time interval before the next succeeding valve is opened and during which all said valves are closed, to thereby build up the vacuum in said conduit means downstream of said valves so that when said next succeeding valve is opened, a sudden and violent implosion of said wastes and air into and through said next succeeding valve and its station occurs, means for intermittently unloading said waste collecting means during each implosion, said unloading means comprising a check valve preventing flow of air from said waste receiving means to a substantial volume of said conduit means adjacent the inlet valves but permitting flow in the reverse direction, said unloading means also comprising means for intermittently removing waste accumulated in said waste receiving means and means synchronized with the control means for said inlet valves to (a) release the vacuum in said waste receiving means and to open said waste removal means to unload said waste receiving means each time an inlet valve is opened and an implosion is initiated and (b) to deactuate said vacuum releasing means and to close said waste removing means to thereby restore the vacuum in said waste collection means each time an inlet valve is closed to initiate a dwell period.

1111. Apparatus according to claim 10, said unloading means also including a vacuum cutoff valve located between said waste receiving means and said pump and synchronized with said inlet valve control means to open each time said inlet valve is closed and to close each time said inlet valve is opened, whereby during each dwell period a vacuum is built up in said conduit system and in said waste receiving means for the next implosion and imploded waste is moved from said volume of said conduit into said waste receiving means and whereby during the next succeeding implosion period such waste is unloaded from said waste receiving means.

12. Apparatus according to claim llll, said vacuum being released by a slot in said cutoff valve, which, when said valve is closed, provides communication between said waste receiving means and the atmosphere to thereby release the vacuum in said waste receiving means 13. Apparatus according to claim 12, said inlet valve con trol means comprising multicam-controlled multiswitches controlled by a synchronized motor so that said inlet valves are actuated intermittently and automatically and repetitively in time sequence by sequential activation of said switches, and cutoff valve and waste removing means being also controlled by said multiswitch control and synchronized motor.

14. Apparatus according to claim 13, each of said cutoff valve and said waste removing means being controlled by an electrically actuated solenoid wired to said inlet valve control lid means so that the actuation of each switch to energize and open an inlet valve deenergizcs said solenoids to close said cutoff valve and open said waste removing means and so that the actuation of each switch to close said inlet valve during a dwell time interval completes a circuit through said switches to energize said solenoids to open said cutofi valve and close said waste removing means.

115. in an apparatus for removing industrial wastes from a plurality of stations, each station comprising at least one inlet at which wastes accumulate, a vacuum pump, waste receiving means and a conduit system interconnecting said stations, said waste receiving means and said pump, an inlet valve for each station, control means for automatically, sequentially, intermittently and repetitively opening and closing said valves according to a timed program, a vacuum cutoff valve between the waste collecting means and the pump, means for venting the waste receiving means to the atmosphere when said cutoff valve is closed but not when said cutofl? valve is open, means for preventing flow of air from said waste receiving means to a substantial volume of said conduit system adjacent said inlet valve but permitting flow of air in an opposite direction, said waste receiving means having a waste removal door and means controlled by said control means for controlling said cutoff valve, said venting means and said door to intermittently release the vacuum in and unload said waste receiving means in synchronization with said intermittent opening and closing of said inlet valves.

to. In a vacuum cleaning apparatus for creating repetitive, intermittent implosions of waste into an inlet of a conduit system having therein means for collecting said imploded waste and means for creating a vacuum in said conduit system and waste collecting means, said waste collecting means having a door to remove collected waste, the improvement comprising first valve means to intermittently open and close communication between said vacuum creating means and said waste collecting means, vent means for venting said waste collecting means, means to open said vent means to vent said waste receiving means to release the vacuum therein when communication between said vacuum-creating means and said waste collecting means is closed by said first valve means and to close said vent means when said communication is open, second valve means to (a) close communication between said waste receiving tank and at least a substantial portion of said conduit system adjacent said inlet when said receiving tank is vented to release the vacuum therein and to (b) open said last mentioned communication when said waste collecting means is in communication with said vacuum creating means, and means for opening said door when said first valve means is closed and said vacuum is released and to close said door when said first valve means is open and said vent means is closed.

117. An apparatus according to claim 116, said inlet being provided with an implosion valve which is intermittently opened and closed to create said implosions, control means to (l) actuate said first valve means to close the same, (2) open said vent means to release the vacuum in said waste collecting means, (3) actuate said second valve means to close the same and (4) actuate said door to open the same when said implosion valve is opened to thereby create an implosion at said inlet and remove waste previously collected in said waste collecting means, and (5) actuate said first valve means to open the same, (6) actuate said vent means to close the same, (7) actuate said second valve means to open the same and (8) actuate said door to close the same when said implosion valve is closed to thereby build up a vacuum in said conduit system and said waste collecting means.

t i 0 t 

1. In a vacuum cleaning apparatus for applying a vacuum by a vacuum pump to an accumulation of waste to suck said waste into an inlet of a piping system having therein waste receiving means for collecting said waste and having a first piping section providing communication between said inlet and said waste receiving means and a second piping section providing communication between said waste receiving means and said pump, the improvement comprising in combination a one-way check valve between said inlet and said waste receiving means for preventing backflow of air from said waste receiving means to a substantial portion of said first piping section adjacent said inlet but permitting free flow of air in an opposite direction, a vacuuM cutoff valve in said second piping section for intermittently cutting off said pump from said waste receiving means during an unloading operation, means for automatically opening said waste receiving means to the atmosphere to release vacuum in said waste receiving means when said cutoff valve is closed but not when said cutoff valve is open, said waste receiving means having a waste removing door and means for automatically opening said door when said cutoff valve is closed and said vacuum is released and for automatically closing said door when said cutoff valve is opened.
 2. In a vacuum cleaning apparatus for intermittently and repetitively applying a vacuum to a waste accumulation point to suck waste into an inlet of a conduit system having therein waste receiving means for collecting said waste, said apparatus including a vacuum pump for applying said vacuum, the improvement comprising means for intermittently and repetitively unloading said waste receiving means each time a vacuum is applied to said inlet, said unloading means comprising, a one-way check valve between said waste receiving means and said inlet preventing the flow of air from said waste receiving means to a substantial portion of said conduit means adjacent said inlet but permitting free flow of air in an opposite direction, a vacuum cutoff valve between said waste receiving means and said pump which is closed each time a vacuum is applied to said inlet, means for releasing the vacuum in said waste receiving means when said cutoff valve is closed, said waste receiving means including a waste removing door and means to open said door when said cutoff valve is closed and to close said door when said cutoff valve is opened.
 3. Apparatus according to claim 2, including an inlet valve associated with said inlet and located between said inlet and said one-way valve, and control means to (a) intermittently, repetitively and automatically open and close said inlet valve and to (b) intermittently and automatically close said shutoff valve and open said door when said inlet valve is opened and to open said cutoff valve and close said door when said inlet valve is closed.
 4. Apparatus according to claim 3, the volume of the conduit means between said one-way valve and said inlet valve at the degree of vacuum delivered by the pump being sufficient to suck the desired amount of accumulated waste at said accumulation point through said inlet valve into said conduit system when said inlet valve is opened and said one-way valve is closed, said one-way valve being closed by the release of vacuum in said waste receiving means.
 5. An apparatus according to claim 3, said unloading means being synchronized with said implosions.
 6. In a vacuum cleaning apparatus for automatically creating repetitive, intermittent implosions of waste into an inlet of a piping system having therein waste receiving means for collecting said imploded waste, the improvement comprising a one-way check valve located between said waste receiving means and said inlet to prevent the flow of air in a direction from said waste receiving means to said inlet but to permit the flow of air in a reverse direction, means for intermittently building up a vacuum in said piping system during a dwell period between implosions and means located between said waste receiving means and said vacuum buildup means to intermittently shut off communication therebetween and vent said waste receiving means to atmosphere for intermittent unloading of said waste receiving means.
 7. In an apparatus for removing and conveying industrial wastes from an accumulation point comprising a vacuum pump, waste receiving and collecting means and a conduit system having an inlet located at said accumulation point and providing communication between said inlet and said waste collecting means and between said waste collecting means and said pump, an inlet wave associated with said inlet and means for actuating said valve to automatically, intermittently and repetitively oPen and close said valve, the improvement comprising means for intermittently unloading said waste collecting means at a time when said valve is opened, said means for unloading said waste collecting means including a shutoff valve between said waste collecting means and said pump, which is automatically closed each time said inlet valve is opened and is automatically opened each time said inlet valve is closed, means automatically actuatable to open said waste collecting means to the atmosphere when said shutoff valve is closed and to close said waste collecting means to the atmosphere when said shutoff valve is open, a one-way valve for preventing flow of air from the waste collecting means to at least a substantial portion of said conduit means adjacent said inlet valve but permitting flow of air in a reverse direction, a door for said waste collecting means and means for automatically closing said door when said shutoff valve is opened and opening said door when said shutoff valve is closed.
 8. Apparatus for removing and conveying industrial wastes from a plurality of stations, each station comprising at least one waste inlet at which wastes accumulate, vacuum pump means, waste receiving and collecting means, conduit means providing communication from each of said stations to said waste receiving and collecting means and from said last-mentioned means to said pump means, an inlet valve for each of said stations and control means for automatically opening and closing said valves successively and repetitively in accordance with a predetermined time program in which each valve is open during a first predetermined time interval and is closed for a second predetermined dwell time interval before the next succeeding valve is opened and during which all said valves are closed, to thereby build up the vacuum in said conduit means downstream of said values so that when said next succeeding valve is opened, a sudden and violent implosion into and through said next succeeding valve and its station occurs and means for intermittently unloading the waste which collects in said waste collecting means without interrupting the repetitive implosions at said stations, said unloading means including a check valve preventing flow of air from said waste receiving means to a substantial volume of said conduit means adjacent said inlet valves but permitting flow in the opposite direction, said unloading means also comprising a waste removal door associated with said waste receiving means and means for releasing the vacuum in said waste receiving means and opening said door when an inlet valve is opened and for deactuating said vacuum release means and closing said door when said inlet valve is closed.
 9. Apparatus according to claim 8, also including a vacuum cutoff valve located between said waste receiving means and said pump and synchronized with said inlet valve control means and said vacuum release means and said door to close when said inlet valve is opened and to open when said inlet valve is closed.
 10. Apparatus for removing and conveying industrial wastes from a plurality of stations, each station comprising at least one waste inlet at which wastes accumulate, vacuum pump means, waste receiving and collecting means, conduit means providing communication from each of said stations to said waste collecting means and from said waste receiving means to said pump means, an inlet valve for each of said stations to individually open and close communication between said stations and said conduit means and control means to automatically open and close said valves successively and repetitively in accordance with a predetermined time program in which each valve is open during a first predetermined time interval and is closed for a second predetermined dwell time interval before the next succeeding valve is opened and during which all said valves are closed, to thereby build up the vacuum in said conduit means downstream of said valves so that when said next succeeding valve is opened, a sudden and violent implosion of said wastes and air into and through said next succeeding valve and its station occurs, means for intermittently unloading said waste collecting means during each implosion, said unloading means comprising a check valve preventing flow of air from said waste receiving means to a substantial volume of said conduit means adjacent the inlet valves but permitting flow in the reverse direction, said unloading means also comprising means for intermittently removing waste accumulated in said waste receiving means and means synchronized with the control means for said inlet valves to (a) release the vacuum in said waste receiving means and to open said waste removal means to unload said waste receiving means each time an inlet valve is opened and an implosion is initiated and (b) to deactuate said vacuum releasing means and to close said waste removing means to thereby restore the vacuum in said waste collection means each time an inlet valve is closed to initiate a dwell period.
 11. Apparatus according to claim 10, said unloading means also including a vacuum cutoff valve located between said waste receiving means and said pump and synchronized with said inlet valve control means to open each time said inlet valve is closed and to close each time said inlet valve is opened, whereby during each dwell period a vacuum is built up in said conduit system and in said waste receiving means for the next implosion and imploded waste is moved from said volume of said conduit into said waste receiving means and whereby during the next succeeding implosion period such waste is unloaded from said waste receiving means.
 12. Apparatus according to claim 11, said vacuum being released by a slot in said cutoff valve, which, when said valve is closed, provides communication between said waste receiving means and the atmosphere to thereby release the vacuum in said waste receiving means
 13. Apparatus according to claim 12, said inlet valve control means comprising multicam-controlled multiswitches controlled by a synchronized motor so that said inlet valves are actuated intermittently and automatically and repetitively in time sequence by sequential activation of said switches, and cutoff valve and waste removing means being also controlled by said multiswitch control and synchronized motor.
 14. Apparatus according to claim 13, each of said cutoff valve and said waste removing means being controlled by an electrically actuated solenoid wired to said inlet valve control means so that the actuation of each switch to energize and open an inlet valve deenergizes said solenoids to close said cutoff valve and open said waste removing means and so that the actuation of each switch to close said inlet valve during a dwell time interval completes a circuit through said switches to energize said solenoids to open said cutoff valve and close said waste removing means.
 15. In an apparatus for removing industrial wastes from a plurality of stations, each station comprising at least one inlet at which wastes accumulate, a vacuum pump, waste receiving means and a conduit system interconnecting said stations, said waste receiving means and said pump, an inlet valve for each station, control means for automatically, sequentially, intermittently and repetitively opening and closing said valves according to a timed program, a vacuum cutoff valve between the waste collecting means and the pump, means for venting the waste receiving means to the atmosphere when said cutoff valve is closed but not when said cutoff valve is open, means for preventing flow of air from said waste receiving means to a substantial volume of said conduit system adjacent said inlet valve but permitting flow of air in an opposite direction, said waste receiving means having a waste removal door and means controlled by said control means for controlling said cutoff valve, said venting means and said door to intermittently release the vacuum in and unload said waste receiving means in synchronization with Said intermittent opening and closing of said inlet valves.
 16. In a vacuum cleaning apparatus for creating repetitive, intermittent implosions of waste into an inlet of a conduit system having therein means for collecting said imploded waste and means for creating a vacuum in said conduit system and waste collecting means, said waste collecting means having a door to remove collected waste, the improvement comprising first valve means to intermittently open and close communication between said vacuum creating means and said waste collecting means, vent means for venting said waste collecting means, means to open said vent means to vent said waste receiving means to release the vacuum therein when communication between said vacuum-creating means and said waste collecting means is closed by said first valve means and to close said vent means when said communication is open, second valve means to (a) close communication between said waste receiving tank and at least a substantial portion of said conduit system adjacent said inlet when said receiving tank is vented to release the vacuum therein and to (b) open said last mentioned communication when said waste collecting means is in communication with said vacuum creating means, and means for opening said door when said first valve means is closed and said vacuum is released and to close said door when said first valve means is open and said vent means is closed.
 17. An apparatus according to claim 16, said inlet being provided with an implosion valve which is intermittently opened and closed to create said implosions, control means to (1) actuate said first valve means to close the same, (2) open said vent means to release the vacuum in said waste collecting means, (3) actuate said second valve means to close the same and (4) actuate said door to open the same when said implosion valve is opened to thereby create an implosion at said inlet and remove waste previously collected in said waste collecting means, and (5) actuate said first valve means to open the same, (6) actuate said vent means to close the same, (7) actuate said second valve means to open the same and (8) actuate said door to close the same when said implosion valve is closed to thereby build up a vacuum in said conduit system and said waste collecting means. 